Pro tips: Winter gardening in the Upland South and Mississippi River Plain, U.S.A. (flowers, growing)

[Sun Belt-lover L.A.M.]

This took me quite some effort, research and time to write. I've piled up some knowledge over the years. Hopefully this guide is helpful for those of you who live in northern Alabama, Arkansas, D.C., northern Georgia, warmer parts of southern Kentucky, the Missouri Bootheel, North Carolina's Piedmont, Oklahoma, highland South Carolina, Tennessee or the Virginia Piedmont! Anything to add?

Bamboo:
Cane brakes of "River Canes" (actually a type of bamboo) are a better alternative than Asian bamboo species, as River Canes are actually native to southeastern North America. However, these do best along ponds/lakes, along streams and in valleys, as they prefer a damp site despite being maintained by a decent fire regime. If you live in a flat area and want to grow them, but don't have any streams, I recommend building a pond (tips here). I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.

Small Flowers:
If you want a wild look, you could allow henbit to spread into your yard/flowerbed. While they're not technically native to North America, they have naturalized and don't pose a serious threat (especially not to trees/shrubs) in the way Kudzu and Asian bamboos do. In fact, they're not even poisonous when consumed, raw or cooked!
On the other hand, if you want a garden look, your best option is the Winter Pansy. These will overwinter reasonably well down to Zone 6a, bloom some all winter down to Zone 7a and bloom fully all winter down to Zone 8a. Also, the array of colors you can get from pansies is just wonderful! Partial shade is a good amount of light for them. However, if they start wilting in May or June, don't bother watering nor shading them; it's the heat that's killing them, and there's nothing you can do except replace the cool-season annuals in mid to late October.
In both cases, they may help bees get the early spring stuff started in mid February and mid spring stuff started in mid March (stuff starts blooming earlier here in the subtropics), as both henbit and pansies are self-pollinating and could provide bees with their first nectar upon emerging in the first few days of consecutive 55-60F+ highs.

Small Trees:
American Holly is one good option for this. They're known to tolerate part shade as they can grow in the understory of hardwood forests, and this lists them as fully shade tolerant. In addition to the evergreen leaves, unique leaf shape and lush foliage color, female also bear colorful berries in winter if a male pollinates them! I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.
If you want a good rainforest feel but don't feel like wrapping tropical trees nor confining plants to your house, Great Rhododendron would be a good option. They're native to the Appalachian Rainforest of East Tennessee and western North Carolina, growing in the understory in partial shade. They're reasonably hardy to Zone 6a and a solid Zone 7a performer. For those of you summer-lovers, they also produce clusters of large white to purple flowers each June and/or July! I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.
If you want shrubs, Mountain Laurel is a good option. The foliage color with these is even more lush-looking than the other two, fully resembling the tropical look most of our deciduous trees have from April to October. They don't do well in full sun, however, and their May flowers only last a few days. I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.

Large Trees:
The best bet you have for large conifers that aren't deciduous and are actually native to North America is Virginian Juniper. However, they don't do well in shade and grow slowly, so Eastern White Pine may be your best bet in certain situations. In either case, be sure to properly protect them from deer until they're big enough! I also recommend fertilizing every April until they get too big for the deer to seriously harm so their growth speeds up. I recommend planting in mid December to early February, when the trees are least likely to be growing even in the subtropics due to cooler average temperatures. No extra water should be necessary due to the lower transpiration rate in the milder temperatures they're likely to establish in.
For large broad-leaved evergreen trees, Southern Magnolia is the most obvious choice. These are especially shade tolerant and, like Great Rhododendron and Mountain Laurel, lend a reasonably lush/tropical look year-round. Sweetbay Magnolia is also a good option if you live in Zone 7b or 8a, but they're tardily deciduous in Zone 6b; I'm not sure how they react to Zone 7a. I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil. Thankfully, Southern Magnolias are not of any interest to the deer.
If you want to grow Live Oak and don't live in Zone 8a, you're not entirely out of luck. While they may not be as easy to come by, there is a Live Oak species that is hardier than the coastal Live Oak species: Escarpment Live Oak. They're native to Oklahoma, and they pass Zone 7a winters just as solidly as a Southern Magnolia or Needle Palm would, even making 6a winters with little protection! I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.
If you want a tree that provides winter interest without keeping its leaves, River Birch is a good bet. They don't do well on summits, however, as they prefer areas where at least some runoff will go towards them. They're also not a good shade tree. However, if you manage and are willing to tolerate the lack of leaves, their colorful bark is very attractive.
If you insist on shade trees, Eastern White Pine and River Birch are your best bets for shade in less time, or Southern Magnolia and Escarpment Live Oak for longer time before you get shade but more of it.

Non-Woody Shrubs:
If you want a desert feel in a more humid region, then you've come to the right place. Eastern Prickly Pear is the ideal native cactus for this region, and Adam's Needle Yucca is a good choice alongside it. If you want it to REALLY feel desert-like, you could add rocks to the area and use stone bricks to keep them from rolling out into the grass, road, stream, pond, driveway or whatever. However, these need full sun and little competition. I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November. They shouldn't need any extra water, however, as they are obviously quite drought tolerant to say the least. Thankfully, cacti and yuccas are not of any interest to the deer.
For a good desert-like tree, Virginian Juniper is your best bet. They look scrubby to some people, and they're closely related to the arid-preferring Rocky Mountain Juniper and grow in the desertlike "Cedar Glades" around the Tennessean major cities of Nashville and Murfreesboro.

Tropical-Looking Plants:
If you want an actual tropical-looking plant that will survive the winters without going dormant, DO NOT PLANT JAPANESE BANANA NOR CHINESE WINDMILL PALM! The former will go dormant; even the trunk isn't perennial. The latter is very hard to grow, especially in hot-summer climates and sandy soil; not to mention their vulnerability to the polar vortex (I've seen dead ones in Hendersonville, Baxter, Algood and Knoxville).
Your best bet for a tropical-looking plant in the Upland South is either the Needle Palm or the Dwarf Palmetto. While many people don't like the look of palms in a non-coastal, non-desert environment, putting them near a body of water, in your desert garden (mentioned above), near your pond or even near your pool could make up for it. If you think they look too "scrubby," you could prune the lower leaves on your Needle Palm as they grow, exposing the trunk. Also, they are popular under shade trees, especially Live Oak (see Large Trees for advice on shade trees and Live Oaks). Both types of Dwarf Palm are solid Zone 7a performers, extremely shade tolerant and extremely flood tolerant. I recommend planting in April, shortly after the last light freeze, to give them enough time to establish before hard freezes in November; water regularly for a while unless it rains often, especially if there's a summer drought and/or you have sandy soil.
Thankfully, Needle Palms are not of any interest to the deer. With their hardiness, size, tough evergreen leaves and nasty thorns, a hedge of them could even be a good defense against deer for your other plants in the long run.

Stabilizing Crop Fields For The Winter or Keeping A Green Field Year-Round:
Crimson Clover and Winter Wheat are both good options for this. With the former hardy to Zone 6a and latter 5b, both should be bulletproof in Zones 7 and 8. If you sow the seeds in early to mid October, they'll still have much warmth and a little heat to take off in but will have less competition in November after some hard freezes.
Also, Crimson Clover does bloom around late March to mid April, with crimson-colored flowers as the name suggests. They may even be a good choice for your yard if the dormant Bermuda Grass and/or rough Crabgrass bothers you, as they aren't problematic in either way and still have the uniformly lush green color most people want for their yards.